It lies off the main coast of the Kyushu island, near the entrance of the Ariake Sea lagoon.
It is connected with the Nomo Peninsula on mainland Kyushu through a causeway over an islet of Nakajima, and the Kabashima Bridge, constructed in 1986.
East Rocks is a low reef which lies northeast of the island.
[3] The habitat of the giant mottled eel, a Natural Monument of Japan, is located on the island.
In 2013, a floating offshore wind turbine was tested about 1 km off the coast of the island.